How do the outer layers of cells on the underside of a leaf work to gather carbon dioxide?

The cells of a leaf are sandwiched in between two layers of epidermal cells, which provide the leaf with a waxy, nearly impermeable cuticle that protects against water loss. ... These intracellular spaces, along with the moist surface of mesophyll cells, facilitate the exchange of carbon dioxide and oxygen.

both anaerobic and aerobic respiration use glucose (or other carbohydrates), proteins and lipids to produce atp and nadh. cell uses those energy molecules, obtained from food and   breaks them down during the chemical reactions of respiration. in anaerobic respiration, nadh is regenerated to nad+ by enzymes lactate dehydrogenase (lactate is produced, e.g. in muscle cells) or by alcohol dehydrogenase where ethanol is produced (alcohol fermentation), while in aerobic respiration, electrons from nadh are deposited in the mitochondria to regenerate nad+ (electron transport chain. anaerobic respiration produces 2 atp per molecule of glucose compared to aerobic respiration where about 38 atp molecules are produced.